1. Field of the Invention
The present invention relates to an image generating apparatus and a thermal transfer printer, and more particularly, it relates to an image generating apparatus and a thermal printer each comprising a paper discharge roller.
2. Description of the Background Art
A thermal transfer printer discharging a printed paper in a state held between a paper discharge roller and a paper support roller coming into contact with the paper discharge roller with prescribed pressing force is known in general. The structure of an exemplary conventional thermal transfer printer 100 is described with reference to FIG. 11.
As shown in FIG. 11, the exemplary conventional thermal transfer printer 100 comprises a chassis 101, an ink sheet cartridge 102 storing an ink sheet 102a, a feed roller 103, a press roller 104 pressing the feed roller 103 with prescribed pressing force, a print head 105 for printing, a platen roller 106 opposed to the print head 105, a paper feed roller 107, a paper discharge roller 108, a paper press roller 109, a spring member 110 for pressing the paper press roller 109 with prescribed pressing force, a lower paper guide 111 and an upper paper guide 112.
The chassis 101 is provided with an ink sheet receiving hole 110a for receiving the ink sheet cartridge 102. The ink sheet cartridge 102 inserted into the ink sheet cartridge receiving hole 110a stores the ink sheet 102a. 
The feed roller 103 is rotatably provided on the chassis 101, and has a function of carrying a paper 150 in a paper feed direction (along arrow A in FIG. 11) and a paper discharge direction (along arrow B in FIG. 11). The press roller 104 presses the feed roller 103 with the prescribed pressing force. Thus, the paper 150 can be held between the feed roller 103 and the press roller 104 and carried in the paper feed direction (along arrow A in FIG. 11) and the paper discharge direction (along arrow B in FIG. 11) in the state held between the rollers 103 and 104. A head portion 105a for printing is provided on the print head 105 rotatably about the support shaft 105b, and rotated toward the platen roller 106 for printing.
The paper feed roller 107 is provided for feeding the paper 150 to a printing position for performing printing with the head portion 105a of the print head 105. The paper discharge roller 108 is provided for discharging the printed paper 150 subjected to the printing with the head portion 105a of the print head 105. The paper press roller 109 has an axial center perpendicularly separated from the axial center of the paper discharge roller 108 at a prescribed interval. In other words, the perpendicular positions of the axial centers of the paper discharge roller 108 and the paper press roller 109 coincide with each other. The paper press roller 109 comes into contact with the paper discharge roller 108 with prescribed pressing force through the spring member 110. Thus, the printed paper 150 subjected to the printing with the head portion 105a of the print head 105 can be held between the paper discharge roller 108 and the paper press roller 109 and carried in the paper discharge direction (along arrow B in FIG. 11) in the state held between the rollers 108 and 109.
The lower paper guide 111 is set in the vicinity of the paper feed roller 107. This lower paper guide 111 has a function of passing the paper 150 fed by the paper feed roller 107 through the upper surface of the lower paper guide 111 in paper feeding thereby guiding the paper 150 to a paper feed path toward the print head 105. The upper paper guide 112, supported by the lower paper guide 111, has a function of passing the paper 150 carried by the feed roller 103 through the upper surface of the upper paper guide 112 thereby guiding the paper 150 to a paper discharge path of the paper discharge roller 108.
An ink jet recording apparatus is also generally as an exemplary image generating apparatus comprising a carrier roller, as disclosed in Japanese Patent Laying-Open No. 2003-191552, for example.
In this ink jet recording apparatus disclosed in Japanese Patent Laying-Open No. 2003-191552, a suction hole is provided on the outer peripheral surface of a paper discharge drive roller (paper carrying roller), and a fan unit is connected to the paper discharge drive roller for sucking air through the suction hole. Thus, a paper carried by the carrier roller (feed roller) is discharged by driving the paper feed drive roller while adsorbing the paper on the outer peripheral surface of the paper discharge drive roller.
However, the conventional thermal transfer printer 100 shown in FIG. 11 must disadvantageously be provided with the spring member 110 pressing the paper press roller 109 against the paper discharge roller 108 with the prescribed pressing force, in order to discharge the printed paper 150 held between the paper discharge roller 108 and the paper press roller 109 coming into contact with the paper discharge roller 108 with the prescribed pressing force. Therefore, the number of components is disadvantageously increased.
In the ink jet recording apparatus disclosed in the aforementioned Japanese Patent Laying-Open No. 2003-191552, the suction hole must be provided on the outer peripheral surface of the paper discharge drive roller while the fan unit must be connected to the paper discharge drive roller, in order to discharge the paper carried by the carrier roller. Consequently, a paper discharge mechanism for discharging the paper is disadvantageously complicated.